Construction of musical instruments has for millennia presented a challenge to the world's artisans. Many competing requirements of a fine instrument must be balanced by the craftsman. Paramount is the maintenance of the proper relationship of the notes sounded. In addition the instrument should permit accurate manipulation to give the musical performer the creative response desired. Secondary requirements from a musical standpoint, but of keen interest from an economic standpoint, are the appearance and cost of the instrument.
Guitars of one sort or another have been played since at least the sixteenth century. Early guitars were of hollow body construction. The hollow body provided resonance and acoustical amplification to the plucked strings. So long as the guitar was played in chamber groups and before small audiences, the natural sounding of the hollow body acoustic guitar was of sufficient volume. With the increasing use of the guitar as an accompanying and lead instrument in twentieth century popular music, great strides were made in producing instruments which could carry to a larger audience, and which could be heard within a multi-piece band. The development of an acoustic guitar with great volume culminated with the large guitars of the 1930's, for example the Martin D-28 and the Gibson archtop Super 400.
Changing musical styles and performance venues, however, placed demands in terms of volume which even the most advanced acoustical designs could not satisfy. Popular performers required instruments which could penetrate the high ambient noise of a honkytonk or crowded dance hall. Many pioneer guitar designers worked to address the problem by providing electric amplification to the vibration of the guitar strings. Adolph Rickenbacker produced a prototype electric guitar in 1931. Known as the "Frying Pan," this elemental electric guitar consisted of a wooden neck connected to a minimal solid body. This guitar employed a simple transducer or pickup comprised of two horseshoe magnets enclosing a coil beneath the strings. In a guitar pickup, vibrations of the metal guitar strings induce a current in the coil, which is then conveyed by a cord or cable to a separate amplifier.
By providing artificial amplification to the vibrations of the strings, the shape of the guitar body was freed from the restrictions imposed by acoustic design considerations. An extreme example of this was the prototype solid body electric guitar designed by Les Paul in 1939-1941 known as "The Log." This guitar connected a wooden guitar neck to a rectangular block of wood with pickups mounted on it. The traditional S-curved sides of an acoustic guitar were merely screwed onto the central block--serving only an ornamental purpose.
Further developments in solid body guitar construction included the Fender Broadcaster and Telecaster of 1950-1951, and the Fender Stratocaster of 1954. Both body styles became extremely popular, and variations of these instruments, as well as accurate replicas, are still manufactured and played today.
Solid body guitar construction, although requiring less demanding construction techniques than the thin wood bending required for acoustic guitars, is nonetheless an exacting process. Guitar performers desire an instrument that will stay "in tune" through protracted performances, that will be responsive to minute variations in performance technique, and that will yield a satisfying and rich sound. The timbre or "tone" of the guitar is of almost mystical concern to guitar players and afficionados, and each guitar manufacturer takes exquisite care to address this concern. While the independent guitar maker may painstakingly custom craft each instrument to achieve the desired results, the mass producer of guitars must, in order to keep costs at a reasonable level, work from a design which is repeatable and consistent.
The wooden guitar neck is subject to twisting or bending towards the body. This bending results from the high levels of tension applied to the metal strings which extend from the tuning heads fixed to the headstock at the far end of the neck to the bridge located at the far end of the body. The strings tend to cause the wood of the neck to bend about the neck-body joint, impairing playability and intonation. The conventional response to neck bending is to insert a metal truss rod into a channel in the neck, and to tighten the rod to counteract the bending. This simple truss rod is not a complete answer however, because the counteracting forces of the simple truss rod do not exactly balance the bending imposed by the strings. The bow of the wood neck due to temperature and humidity varies with the seasons. In addition, it varies with different string gauges and tunings. Martin Guitars manufactures a truss rod assembly having a U-shaped channel with a single spacer on a threaded rod positioned closer to the headstock end of the channel than to the body end. Yet this assembly still fails to eliminate distortion of the neck.
Necks having greater cross-sectional area will be stiffer and hence offer greater resistance to bending. Yet from a player's perspective, a thinner neck is desirable for its improved playability.
What is needed is a guitar of economical construction with structural features which preserve the position of the neck with respect to the body to provide an instrument of improved stability and tone.